Goodwill and Other Intangibles (Details)	12 Months Ended
	Dec. 25, 2016 USD ($) restaurant item	Dec. 27, 2015 USD ($) restaurant item	Dec. 28, 2014 USD ($)
Goodwill
Goodwill, Beginning Balance	$ 79,657,000	$ 82,007,000
Acquisitions	10,166,000	135,000
Divestitures	(2,481,000)
Reclassification to assets held for sale	979,000	(1,690,000)
Foreign currency adjustments	(2,792,000)	(795,000)
Goodwill, Ending Balance	$ 85,529,000	$ 79,657,000	$ 82,007,000
Number of restaurants acquired | restaurant		7
Number of domestic markets in which acquired restaurants | item		3
Number of restaurants sold | restaurant	42
Number of domestic markets in which restaurants sold | item	1
Goodwill impairment loss	$ 0	$ 0	0
Franchise Rights
Goodwill
Finite-lived intangible assets	2,400,000	700,000
Accumulated amortization	800,000	400,000
Amortization expense	400,000	200,000	200,000
China Operations
Goodwill
Reclassification to assets held for sale	979,000
Domestic Company-owned Restaurants
Goodwill
Goodwill, Beginning Balance	62,363,000	62,228,000
Acquisitions	10,166,000	135,000
Divestitures	(2,481,000)
Goodwill, Ending Balance	$ 70,048,000	62,363,000	62,228,000
Number of restaurants acquired | restaurant	25
Number of domestic markets in which acquired restaurants | item	4
International
Goodwill
Goodwill, Beginning Balance	$ 16,858,000	19,343,000
Reclassification to assets held for sale	979,000	(1,690,000)
Foreign currency adjustments	(2,792,000)	(795,000)
Goodwill, Ending Balance	15,045,000	16,858,000	19,343,000
Goodwill, accumulated impairment	2,300,000	2,300,000	2,300,000
All others
Goodwill
Goodwill, Beginning Balance	436,000	436,000
Goodwill, Ending Balance	$ 436,000	$ 436,000	$ 436,000